Author(s): Julien Lhomme, Jonathan Klaric, David Fortune
Linked Author(s): Sudesh Mudaliar
Keywords: Sustainable drainage, LIDs, WSUD, SuDS, SWMM
Abstract: Green Stormwater Infrastructures are now commonly used in urban and peri-urban developments or retro-fitted operations in many countries around the world. However the representation of the flow and pollutant movements in these structures for design or modelling purposes is still a matter of research, development and investigation. This study compares two approaches for the representation of Green Stormwater Infrastructures as part of a drainage system: (i) a conceptual representation of the hydraulic processes based on a Muskingum routing scheme, and (ii) a physics-based representation of the hydraulic processes using the core calculations of EPA SWMM5 for Low Impact Developments (LID) (although modified to be used as network components and not as part of a catchment). The two approaches are compared on a simple study case featuring a sustainable drainage structure connected to a conventional drainage network. Differences in the respective algorithms are scrutinized to explain the differences in results. The comparison of the results given by the two engines highlighted the critical parameters that are common between the two engines which allow the engines to give very similar results with the appropriate setup. Assumptions made in the physics-based approach lead to the absence of attenuation and delay in the outflow hydrograph. This appears to be a deficiency and will be addressed in the future
Year: 2017